断点

每天进步一点点!
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今天在选择一条记录进行做删除操作时,碰见index失败的问题,如下:
处理失败!错误信息:[SQLException  ORA-01502  index  VHL_V6.PK_WEB_APP_TGT_OBJ  or partition of such index is in unusable state ]
在网上查询了下,知道原因,就上数据库查了一下,结果如下:
1 PK_WEB_APP_TGT_OBJ NORMAL VHL_V6 TABLE UNUSABLE。
显然是UNUSABLE状态,那也就知道原因了,呵呵,解决!

以下为参考文件:

SQL> create table t(a number);
Table created.

1、现在,我们建立一个唯一索引来看看:
SQL> create unique index idx_t on t(a);
Index created.
SQL> select index_name,index_type,tablespace_name,table_type,status from user_indexes where index_name='T';         
no rows selected
SQL> select index_name,index_type,tablespace_name,table_type,status from user_indexes where index_name='IDX_T';
INDEX_NAME                     INDEX_TYPE                  TABLESPACE_NAME                TABLE_TYPE  STATUS
------------------------------ --------------------------- ------------------------------ ----------- --------
IDX_T                          NORMAL                      DATA_DYNAMIC                   TABLE       VALID
SQL> insert into t values(1);
1 row created.
SQL> commit;
Commit complete.

2、将索引手工修改为unusable状态(模拟发生索引失效的情况):
SQL> alter index idx_t unusable;
Index altered.
SQL>  select index_name,index_type,tablespace_name,table_type,status from user_indexes where index_name='IDX_T';
INDEX_NAME                     INDEX_TYPE                  TABLESPACE_NAME                TABLE_TYPE  STATUS
------------------------------ --------------------------- ------------------------------ ----------- --------
IDX_T                          NORMAL                      DATA_DYNAMIC                   TABLE       UNUSABLE
我们看到这是,已经不能正常往表中插入数据:
SQL> insert into t values(2);
insert into t values(2)
*
ERROR at line 1:
ORA-01502: index 'MISC.IDX_T' or partition of sUCh index is in unusable state

3、首先,我们通过重建索引(rebuild index)的方法来解决问题:
SQL> alter index idx_t rebuild;
Index altered.
SQL> select index_name,index_type,tablespace_name,table_type,status from user_indexes where index_name='IDX_T';
INDEX_NAME                     INDEX_TYPE                  TABLESPACE_NAME                TABLE_TYPE  STATUS
------------------------------ --------------------------- ------------------------------ ----------- --------
IDX_T                          NORMAL                      DATA_DYNAMIC                   TABLE       VALID
SQL> insert into t values(2);
1 row created.
SQL> commit;
Commit complete.
SQL>

4、现在我们再次模拟索引失效(unusable状态):
SQL> alter index idx_t unusable;
Index altered.
SQL> select index_name,index_type,tablespace_name,table_type,status from user_indexes where index_name='IDX_T';
INDEX_NAME                     INDEX_TYPE                  TABLESPACE_NAME                TABLE_TYPE  STATUS
------------------------------ --------------------------- ------------------------------ ----------- --------
IDX_T                          NORMAL                      DATA_DYNAMIC                   TABLE       UNUSABLE
SQL> insert into t values(3);
insert into t values(3)
*
ERROR at line 1:
ORA-01502: index 'MISC.IDX_T' or partition of such index is in unusable state

5、然后,看看是否可以通过设置参数skip_unusable_indexes=true来解决问题:
SQL> alter session set skip_unusable_indexes=true;
Session altered.
SQL> insert into t values(3);
insert into t values(3)
*
ERROR at line 1:
ORA-01502: index 'MISC.IDX_T' or partition of such index is in unusable state
SQL> select index_name,index_type,tablespace_name,table_type,status from user_indexes where index_name='IDX_T';
INDEX_NAME                     INDEX_TYPE                  TABLESPACE_NAME                TABLE_TYPE  STATUS
------------------------------ --------------------------- ------------------------------ ----------- --------
IDX_T                          NORMAL                      DATA_DYNAMIC                   TABLE       UNUSABLE
SQL> alter index idx_t rebuild;
Index altered.
SQL> select index_name,index_type,tablespace_name,table_type,status from user_indexes where index_name='IDX_T';
INDEX_NAME                     INDEX_TYPE                  TABLESPACE_NAME                TABLE_TYPE  STATUS
------------------------------ --------------------------- ------------------------------ ----------- --------
IDX_T                          NORMAL                      DATA_DYNAMIC                   TABLE       VALID
SQL> insert into t values(3);
1 row created.
SQL> commit;
Commit complete.
SQL>

总结:对于unique index,通过简单的设置参数是不能解决问题的,要解决unique index 失效的问题,只能通过重建索引来实现。

资料引用:http://www.knowsky.com/388811.html


posted @ 2009-09-26 21:36 断点 阅读(80) | 评论 (0)

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